IC chips, such as microprocessors, coprocessors, and the like often use package devices (“packages”) to physically and/or electronically attach the IC chip to a circuit board, such as a motherboard (or motherboard interface). For certain devices, such as cell phones, laptop computers, and other thin or small electronic devices, it's desirable to use a low height package, such as a “low Z-height package”. To provide a low height package, a “coreless” package may be used such as a package having a thickness no greater than 0.4 mm. Such a coreless package may exclude a support, such as by not having a fiber reinforced polymer support. However, current low height packages suffer drawbacks, such as increased cost, reduced manufacturing rate, and specialized equipment requirements, as compared to improved processes and devices described herein.
For example, some low height coreless packages are manufactured using interconnect layers formed by a polymer, such as ABF, as their dielectric in a direct laser (to form interconnect vias) and lamination (of the polymer) process technology. This manufacturing process is process backend limited and therefore more expensive to manufacture than their “cored” counterparts (e.g. x-2-x, where “x” refers to the build-up layers of the package, “2” refers to the core layers in the package, and 2x is the layer count for the coreless package), despite the coreless packages having two times the productivity. Backend limitations may be due to the more complex build-up layers in the package. In some cases, processing of coreless packages may require forming a cored package and then removing the core so that the package is coreless.
Also, some coreless package processes start with a core followed by pocket formation of conductor openings of the package. One pocket formation that is specific to this type of process technology is known as Direct Laser Lamination (DLL). Since dedicated and completely separate process equipment is needed for pocket formation processes, the package cost is highly driven by the increased cost of these equipment, as well as the lower volume of manufacturing (which is typically very low as the low height package processes are currently considered for only Mobile Internet Device (MID) segments of the industry, such as for handheld internet communication & computing devices).